1. Field of the Invention
The present invention relates to a panel module; and more particularly to a method for maintaining vacuum-tight of a panel module.
2. Description of the Related Art
Panel modules have become a crucial element of a display. The vacuum inside the panel module is highly required and important, which decays performance of components inside the panel module. During the manufacturing process of the panel module, after exhausting inside of the panel module and completing aging process, an exhaust tube connected to the panel module is burnt out and sealed by hydrogen-oxygen torch to maintain vacuum inside the panel module and also assure normal functions of the components inside the panel module. However, because the pressure inside the panel module is smaller than the pressure outside the panel module during an annealing process to use the hydrogen-oxygen torch to heat and seal the exhaust tube, ambient air will flow into the panel module to decrease the vacuum inside the panel module. The performance and functions of the components inside the panel module thus decay.
FIG. 3A and FIG. 3B explains a bottleneck for maintaining vacuum-tight inside a conventional panel module. FIG. 3A is a schematic cross-sectional view of the conventional panel module, in which an exhaust opening of the panel module is connected to a glass tube for exhausting the air inside the panel module. The panel module includes a first substrate 10a, a second substrate 10b and a side frame 11 disposed between the first substrate 10a and the second substrate 10b. An exhaust opening 10c is formed in the second substrate 10b to connect to one end of the glass tube 40 serving as an exhaust tube. The other end of the glass tube is connected to a pumping system 50. The air inside the panel module is exhausted by the pumping system 50 through the exhausting opening 10c and the glass tube 40. After exhausting the inside of the panel module, the glass tube 40 is burnt out and sealed by the annealing process with hydrogen-oxygen torch so as to meet the demand of the vacuum inside the panel module.
However, during the annealing process to use the hydrogen-oxygen torch to heat the glass tube 40 to gradually shrink one end of the glass tube 40, ambient air will flow into the panel module and the vacuum inside the panel module deteriorates. The quality and performance of the components inside the panel module are adversely affected. Accordingly, a method for effectively maintaining the vacuum inside the panel module is desired.